This invention is directed to a rotary motion transformer for effecting a continuous rotation of a rotary member in response to intermittent rotational driving thereof, and in particular to a rotary motion transformer for use in an electronic wristwatch wherein the intermittent rotary motion of the gear train is transformed into continuous rotary motion of the watch hands.
Heretofore motion transformers for converting the reciprocating motion of a stepping motor into a rotational motion have been utilized in electronic wristwatches. A particular disadvantage of such motion transformers is that the stepping motor causes the rotor to be intermittently rotated due to the manner in which excitation signals are applied to the step motor, i.e., the number of rotations of the rotor is determined by the number of pulses per unit of time. Accordingly, a step motor utilized to transform the electrical signal applied into a rotational signal causes the mechanical rotary motion to reflect the application of the electrical signals applied thereto. This is particularly the case when only a few signals per unit of time are applied thereto. The intermittent rotary motion of the rotor is transmitted to the gear train mechanism of the wristwatch, and the gear train is intermittently rotated whether the speed of the gear train movement is increased or reduced. This intermittent rotation of the gear train is clearly perceived by the user of a quartz crystal wristwatch when for example, the second hand is intermittently rotated in a quartz crystal timepiece. Accordingly, it is desirable to provide a smooth, continuous rotation of the clock hands in response to the intermittently rotated gear train.